TABLE 1 .
MICs of different antibiotics and ampC expression levels for strains PAO1 and PA14 and mutants derived from these two strains
| Strain | MIC (µg/ml)a |
Avg level of ampC expression ± SDb | |||||||
|---|---|---|---|---|---|---|---|---|---|
| CAZ | FEP | PIP-TZ | ATM | IMP | MER | VAN | COL | ||
| PAO1 | 1 | 1 | 4 | 1 | 1.5 | 0.38 | 512 | 0.75 | 1 |
| PAΔD | 6 | 4 | 64 | 6 | 1.5 | 1 | 512 | 0.75 | 63.3 ± 7.1 |
| PAΔDDh2 | 16 | 12 | 96 | 16 | 1.5 | 1 | 512 | 0.75 | 79.5 ± 12.2 |
| PAΔDDh3 | 48 | 32 | >256 | 16 | 1.5 | 2 | 512 | 0.75 | 251.2 ± 51.9 |
| PAΔDDh2Dh3 | 48 | 32 | >256 | 32 | 1.5 | 2 | 512 | 0.75 | 1,225 ± 101 |
| PAΔDDh2Dh3 + pUCPAD | 1.5 | 1.5 | 6 | 1.5 | 1 | 0.5 | 512 | 0.75 | 2.9 ± 0.7 |
| PAΔdacB | 32 | 12 | 96 | 16 | 1.5 | 0.5 | 512 | 0.75 | 53 ± 22.2 |
| PAΔdacBΔD | 128 | 64 | >256 | 48 | 2 | 2 | 512 | 0.75 | 1,770 ± 401 |
| PAΔAG | 1 | 1 | 3 | 1 | 0.38 | 0.38 | 512 | 0.75 | −1.1 ± 0.4 |
| PAO1 + pUCPAC | 24 | 16 | 96 | 16 | 1.5 | 1.5 | 512 | 0.75 | 1,925.5 ± 514 |
| PAΔAG + pUCPAC | 24 | 16 | 96 | 16 | 1.5 | 1.5 | 512 | 0.75 | 1,480 ± 359.1 |
| PA14 | 0.75 | 0.5 | 3 | 1 | 1 | 0.125 | 512 | 0.25 | 5.2 ± 2.9 |
| PA14ΔD | 1.5 | 1.5 | 4 | 3 | 1 | 0.19 | 512 | 0.25 | 8.9 ± 1.5 |
| PA14ΔDh2 | 0.75 | 0.5 | 3 | 1 | 1 | 0.125 | 512 | 0.25 | 5.1 ± 1.2 |
| PA14ΔDh3 | 0.75 | 0.5 | 3 | 1 | 1 | 0.125 | 512 | 0.25 | 4.5 ± 2.2 |
| PA14ΔDh2Dh3 | 1 | 0.5 | 3 | 1 | 1 | 0.19 | 512 | 0.25 | 4.7 ± 1.5 |
| PA14ΔDDh2 | 1 | 0.75 | 4 | 1.5 | 1 | 0.125 | 512 | 0.25 | 12 ± 2.1 |
| PA14ΔDDh3 | 16 | 8 | 128 | 16 | 1 | 1.5 | 512 | 0.25 | 4,561 ± 570 |
| PA14ΔDDh2Dh3 | 16 | 8 | >256 | 24 | 1.5 | 1.5 | 512 | 0.25 | 5,569 ± 928 |
| PA14ΔDDh2Dh3 + pUCPAD | 2 | 1.5 | 6 | 3 | 1 | 0.25 | 512 | 0.25 | 152.2 ± 77.1 |
| PA14ΔdacB | 4 | 3 | 8 | 4 | 1 | 0.19 | 512 | 0.25 | 36 ± 10.2 |
| PA14ΔdacBΔD | 8 | 6 | 96 | 12 | 1 | 0.25 | 512 | 0.25 | 114.1 ± 42.1 |
a
Abbreviations: CAZ, ceftazidime; FEP, cefepime; PIP-TZ, piperacillin-tazobactam; ATM, aztreonam; IMP, imipenem; MER, meropenem; VAN, vancomycin; COL, colistin.
b
Relative amount of ampC mRNA compared to the amount expressed in strain PAO1.